I agree with your perspective. My view is that depression can result from physical problems in the brain,dealing with a life problem, genetics, or combinations of these 3 factors. Modern medicine has found physical causes for depression. Basically, it's due to problems in carrying messages across the synapses in the brain and there are medications which can help to fix this. I do believe that our faith and the prayers of other Christians certainly help as do exercise, diet and changes in lifestyle.
I've had issues with depression as has my identical twin brother. I think the problem is largely genetic with us. (We also had to be operated on for a thoracic aortic aneurysm in exactly the same place, right next to the heart!) A deacon in my former church once told me that depression was due to demon possession. Hey, they believed in that sort of thing back in the Middle Ages. I not only get angry at this kind of assertion by someone who is not qualified as an expert in the area of depression. but I believe he's leading people away from getting the professional help they need.
For a person of faith, I believe that the best person to consult with for depression is a Christian Psychiatrist who is qualified in both the medical and emotional aspects of the disease but also in adding the power of Christian counseling. I met such a person in church one Labor Day Sunday when the pastor asked us to turn to the person on both sides and tell them what your profession was. I do not believe this was an accidental meeting. I truly believe that God found for me exactly what I needed at that point in time. So, there is most certainly a place in the treatment for depression for a faith based approach. It's just not the total answer.